目的 应用超声斑点追踪成像技术(STI)观察短期药物干预对自发性高血压大鼠(SHR)左室节段心肌径向(RS)及圆周应变(CS)的变化,探寻较传统超声心动图更早评价左室收缩功能改变的方法.方法 以10只Wistar大鼠为正常对照组,将30只SHR随机分成对照组、硝苯地平组、三子养阴汤组各10只,分别测量左室EF,FS及左室短轴乳头肌水平RS和CS的收缩期峰值.结果 4组大鼠的EF、FS值无明显差异,模型对照组大鼠的PRS和PCS明显降低(P＜0.05),与模型对照组比较,硝苯地平组PRS除了下壁与间隔外,其余4个节段明显升高(P＜0.05),三子养阴汤组6个节段PCS降低,以前间隔、前壁、侧壁、后壁为著(P＜0.05).结论 STI能定量评价左室局部心肌的RS和CS,较传统超声更为敏感.%Objective To investigate the change of left ventricular myocardium radial strain and circumferential strain in spontaneously hypertensive rats ( SHR) with drug intervention for three months by speckle tracking imaging ( STI) and determine a way capable of evaluating the effect of drug intervention on left ventricular function of SHR earlier than conventional echocardiography. Methods Echocardiographic examinations were performed in ten Wistar rats and thirty SHR. The latter were made into normotensive group, nifedipine group and sanziyangying decoction group. Left ventricular fractional shortening (FS) and ejection fraction ( EF) were measured by trasthoracic echocardiography. Radial strain and circumferential strain were measured in the left ventricular shot-axis views with 2D strain software. Results No significant difference in EF and FS were found between the four groups. However, the peak systolic radial strain ( PRS) and circumferential strain ( PCS) of SHR were significantly decreased( P<0. 05). Compared with the SHR model control, the PRS of all segments were increased in the nifedipine group except for the inferial and septal segments( P<0.05). Circumferential peak systolic strain of 6 segments in the sanziyangying decoction group was significantly lower than that of the SHR model control, especially for that of the septal, antelheca, side wall and back wall (P<0. 05). Conclusion STI is superior to the conventional echocardiography on evaluating the myocardial radial strain and circumferential strain in left ventricle.
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